Week - 1-4
monday - rest
Tuesday - HIIT
Weds - 2miles
thurs - Rest
Fri - HIIT
Sat - 1.2miles
sun - 1.2miles
week 5 (test week)
Mon - rest
Tues - rest
weds - 1.2
thurs - rest
fri - rest
sat - 1m (race day)
sun - rest and Beer.
I'm not saying this is 100% the best way to do it, But you wouldnt go far wrong with this. Its always better to train slightly over your goal, or your body will adapt to the disstance your running.
You may like to stick a few longer runs in there just to change things around.
Weight training will also help.
Make sure you include squats and lunges.